RESULTS OF MECHANIC VERSUS MOTORIZED STAPLER USED IN GASTRIC SURGERY: PROSPECTIVE STUDY

ABSTRACT BACKGROUND: Mechanic sutures represent an enormous benefit for digestive surgery in decreasing postoperative complications. Currently, the advantages of motorized stapler are under evaluation. AIMS: To compare the efficacy of mechanic versus motorized stapler in gastric surgery, analyzing rate of leaks, bleeding, time of stapling, and postoperative complications. METHODS: Ninety-eight patients were submitted to gastric surgery, divided into three groups: laparoscopic sleeve gastrectomy (LSG) (n=47), Roux-en-Y gastric bypass (LRYGB) (n=30), and laparoscopic distal gastrectomy (LDG) (n=21). Motorized staplers were employed in 61 patients. The number of firings, number of clips, time of total firings, total time to complete the surgery, and postoperative outcome were recorded in a specific protocol. RESULTS: Patients submitted to LSG, LRYGB, and LDG recorded a shorter time to complete the procedure and a smaller number of firings were observed using motorized stapler (p<0.0001). No differences were identified regarding the number of clips used in patients submitted to LSG. In the group that used mechanic stapler to complete gastrojejunostomy, jejuno-jejuno-anastomosis, and jejunal transection, it was observed more prolonged time of firing and total time for finishing the procedure (p=0.0001). No intraoperative complications were found comparing the two devices used. Very similar findings were noted in the group of patients undergoing LDG. CONCLUSIONS: The motorized stapler offers safety and efficacy as demonstrated in prior reports and is relevant since less total time of surgical procedure without intraoperative or postoperative complications were confirmed.


A QUEDA DA PRESSÃO PORTAL APÓS DESVASCULARIZAÇÃO ESOFAGOGÁSTRICA E ESPLENECTOMIA INFLUENCIA A VARIAÇÃO DO CALIBRE DAS VARIZES E AS TAXAS DE RESSANGRAMENTO NA ESQUISTOSSOMOSE NO SEGUIMENTO EM LONGO PRAZO?
Does the drop in portal pressure after esophagogastric devascularization and splenectomy variation of variceal calibers and the rebleeding rates in schistosomiasis in late follow-up?
Walter de Biase SILVA-NETO 1 , Claudemiro QUIRESE 1 , Eduardo Guimarães Horneaux de MOURA 2 , Fabricio Ferreira COELHO 3 , Paulo HERMAN 3 ABSTRACT -Background: The treatment of choice for patients with schistosomiasis with previous episode of varices is bleeding esophagogastric devascularization and splenectomy (EGDS) in association with postoperative endoscopic therapy.However, studies have shown varices recurrence especially after long-term follow-up.Aim: To assess the impact on behavior of esophageal varices and bleeding recurrence after post-operative endoscopic treatment of patients submitted to EGDS.Methods: Thirty-six patients submitted to EGDS portal pressure drop, more or less than 30%, and compared with the behavior of esophageal varices and the rate of bleeding recurrence.Results late post-operative varices caliber when compared the pre-operative data was observed despite an increase in diameter during follow-up that was controlled by endoscopic therapy.

Conclusion
variceal calibers when comparing pre-operative and early or late post-operative diameters.
The comparison between the portal pressure drop and the rebleeding rates was also not

Perspectives
The motorized stapler offers safety and efficacy as demonstrated in prior reports and is relevant since less total time of surgical procedure without intraoperative or postoperative complications were confirmed.In our experience, the main advantage using motorized stapler is the total surgical time once finished the procedure.A subjective parameter difficult to evaluate is the ergonomic advantage.

Central Message
A high percentage of gastric surgical procedures are performed by laparoscopic approach for benign or malignant diseases and bariatric surgery.The major improvement in the type of devices employed for this surgery allows for diminished postoperative complications like leaks or bleeding from stapled line sutures.It is important to compare the efficacy of mechanic stapler with the motorized device in performing gastric surgery regarding rate of leaks, bleeding, time of stapling, and postoperative complications.
The surgical procedures were performed by only two surgeons (IB and GC), employing laparoscopic procedures, using a mechanic stapler in 37 patients and an Ezisurg ™ motorized stapler in 61 patients.The LSG was performed according to the technique described previously 24,25 .For gastric transection, either a mechanic stapler with a 60-3.5mmsblue cartridge or an Ezisurg ™ motorized stapler was used.Clips or stitches were used to stop excessive bleeding of the suture line after firing.In the LRYGB, the detailed technique described by Brazilian authors was adopted 26,27 .For gastric transection, mechanic stapler 60-3.5 mms blue cartridge and 45-2.5 mms blue cartridge were employed only in a few cases for finishing the transection of the gastric fundus as well as the Ezisurg ™ motorized stapler depending on the availability of the device.
The LDG was performed by only one surgeon (IB), indicated for patients suffering from different esophagogastric benign diseases (Table 1).The techniques adopted were described before 8,9,28,29,30 .During this procedure for gastric transection, mechanic stapler 60-3.5 mms blue cartridge and 45-2.5 mms blue cartridge were used only in a few cases for finishing the transection of gastric fundus.For duodenal transection, gastrojejunostomy, jejuno-jejunostomy, and jejunal transection, only one stapler was employed, either a mechanic 60-3.5 mms blue cartridge stapler or a motorized stapler, also depending on device availability.Clips were used to stop bleeding of the suture line.
The parameters evaluated intraoperatively during surgery were: The use of a mechanic or motorized stapler was chosen depending on the availability of the device at the beginning of the procedure and measurements were established by a nurse during the procedure.Data were recorded in a special protocol designed for this specific study.
Statistical analysis of data was performed with Statistical Package for Social Sciences (SPSS), version 18.0 (IBM Co., Armonk,

INTRODUCTION
A high percentage of gastric surgical procedures are performed by laparoscopic approach for benign or malignant diseases and bariatric surgery.Today, surgery for early and advanced gastric cancer can be undertaken laparoscopically except for large tumors 19,21,36 .Currently, patients with gastrointestinal stromal tumors or long Barrett's esophagus are also submitted to laparoscopic distal gastrectomy (LDG) compared to the 1980s and 1990s decades 8,25,29,31 .Since 1993 we have performed laparoscopic procedures for these patients 5,9,16 .Laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB), the most frequent bariatric procedures worldwide, are conducted with the same approach 10,32 .The major improvement in the type of devices employed for this surgery allows for diminished postoperative complications like leaks or bleeding from stapled line sutures 3,7,12,18,24,30 .
The purpose of this prospective study was to compare the efficacy of mechanic stapler with the motorized device in performing gastric surgery regarding rate of leaks, bleeding, time of stapling, and postoperative complications.

METHODS Patients
This is a prospective study including a total of 98 patients divided into three groups: Group A: Patients submitted to LSG (n=47), divided into two subgroups.The first one using mechanic stapler (n=10) and the second using motorized Ezisurg ™ stapler (n=37); Group B: Patients submitted to LRYGB (n=30), divided into two subgroups.The first using a mechanic stapler (n=14) and the second one using a motorized Ezisurg ™ stapler (n=16); Group C: Patients submitted to LDG (n=21), operated on due to esophageal or gastric diseases (combined with fundoplication and hiatal hernia repair in 18 patients), also divided into two groups depending on the use of mechanic stapler (n=13) and the second one using motorized Ezisurg ™ stapler (n=8).
Table 1 shows the demographic characteristics of each group.A p-value of less than 0.05 was considered significant.
The authors declare that no experiments were performed for this study.All procedures were in accordance with the hospital's bioethics committee and the 1961 Helsinki Declaration, its later amendments, or comparable ethical standards.To ensure patients' data confidentiality, the authors adhered to the hospital's clinical and research protocols for publication.The authors declare that no study patient private data are included in this article and all gave their informed consent before the operation.

RESULTS
The demographic characteristics of the patients included in this study are very similar in terms of age, sex, and body mass index (Table 1).Comparing the comorbidities in patients operated on for morbid obesity undergoing LSG or LRYGB, there are some differences because in patients with gastroesophageal reflux disease (GERD), LSG is not indicated, and these patients are submitted to LRYGB.The other comorbidities are quite similar in these two groups of patients.On the contrary, in patients undergoing distal gastrectomy, there are other causes such as severe esophagitis with Barrett's esophagus, conversion to LRYGB after LSG, or the existence of a gastric tumor (Table 2).
Table 3 shows the results obtained in patients submitted to LSG.No significant differences were observed regarding time, number of firings, and number of clips comparing mechanic with motorized stapler.Excessive bleeding that needed suture reinforcement occurred after the use of mechanic stapler, which was associated to more dragged-on surgical procedure.(48±5.9vs 28±2.51 min) (p=0.0001;p<0.05).In patients undergoing LRYGB, during gastric transection and pouch performing, a little difference regarding the total time of firing in favor of the motorized stapler was noted, probably because this latter device has a shorter cartridge.However, a more prolonged time of firing for performing gastrojejunostomy, jejuno-jejunoanastomosis, jejunal transection, and total time for finishing the procedure was observed in the group using mechanic stapler (p=0.0001;p<0.05) probably due to the waiting time recommended to avoid excessive bleeding of the suture line.
No intraoperative complications were confirmed when comparing the two devices used.(Table 4).Very similar findings were observed in the group of patients undergoing LDG (Table 5).Regarding the postoperative outcome, a prolonged in-hospital stay after mechanic stapler use was identified due to a complication-Clavien-Dindo IIIa (perigastric abscess treated with antibiotics and percutaneous drainage).No other complications and readmissions were reported (Table 6).

DISCUSSION
This study was conducted to compare the early outcome using two different types of staplers in obese patients submitted to LSG, LRYGB, and LDG indicated for Barrett´s esophagus as a primary procedure, redo fundoplication for failed Nissen fundoplication, or conversion to resectional gastric bypass after sleeve gastrectomy 4,9,22,38,43,44 .These procedures are not exempt from postoperative complications including leakage from staple lines, bleeding, and fistula formation 1,13,17,26,27,33,35 .In order to minimize the line suture postoperative complications, the stapling instrument is employed to simplify and optimize the procedure, and facilitate tissue approximation and transection during surgery.These new devices also require less skill from the surgeon.Several different models of motorized staplers (i.e., those for which the staples and knife blade are driven not by manual force but by a power source instead) have been used since 2010.Subsequent versions have been introduced 24,30 .These powered staplers were developed to increase stability and enable more precise stapling relative to non-powered (manual) staplers 42 .
In the literature, few papers focused on the analysis of intraoperative and postoperative outcomes using this type of stapler.Roy et al. 41 reported the results concerning cost, operative time, and in-hospital stay.In this study, the mean hospital stay was 2.1 days for both the powered and manual stapler groups (p=0.981,p>0.05).Total costs of the hospital, mean supply, and mean operating room were significantly less expensive using the powered stapler (p=0.003,p=0.011, and p=0.009, respectively, p<0.05)The operative time, rate     of bleeding and/or transfusions were also significantly lower for the powered stapler group vs the manual stapler group.The adjusted rates of 30 (4.4%), 60, and 90-day all-cause readmissions were similar between the groups (all p>0.05) 41 .
Another study evaluated 60 consecutive LSG procedures-30 sleeves using the AEON™ Endostapler in thick mode and 30 using the ECHELON Flex™ Powered Stapler with pulse technique 37 .The authors assessed stapler performance regarding the incidence and degree of staple line bleeding by visualizing bleeding after the final firing.It was analyzed by a third-party blinded evaluator and given a "bleeding score"-a qualitative measure of intra-operative staple-line bleeding (1= no bleeding to 5= profuse bleeding).The AEON™ Endostapler had 15 cases (50%) with no bleeding at the fundus and the ECHELON Flex™ had 7 cases (23%).The authors concluded that AEON™ Endostapler is a significantly drier alternative to the ECHELON Flex™ Powered Stapler, producing a much drier staple line and decreasing the need for other bleeding control methods 37,40 .
Other reports suggested that the AEON™ Endostapler produces a significantly drier staple line, compared to the ECHELON Flex™ Powered Stapler, and is associated with less interventional control of the staple line 37,43,44 .
Rawlins et al. 37 compared outcomes between the two latest innovations in powered stapling technology-the ECHELON Flex™ GST system (GST) and the SIGNIA™ Stapling System (SIG)-among patients undergoing sleeve gastrectomy for obesity, concerning leak, total hospital costs, length of stay, and operating room time.Then, 30, 60, and 90 days of all-cause inpatient readmissions were also examined.The observed incidence proportion of hemostasis-related complications during surgical admission was lower in the GST group than in the SIG group (0.006% vs 0.020%).Differences between the GST and SIG groups were not statistically significant for leakage, total hospital costs, length of stay, operating room time, and all-cause inpatient readmission at 30, 60, and 90 days.GST system has been associated with a lower rate of hemostasisrelated complications as compared to SIG.A powered stapler with a GST system has demonstrated safety for use in gastric surgery 11,39 .
The beneficial aspects of the powered device may be derived from: a) The combination of increased stability, along with superior control of tissue movement with advanced reloads potentially reducing the cause of trauma to tissue; b) Formation of a more integrated staple line; c) Speed time of firing; d) Less effort during surgery; and e) More favorable cognitive, affective, physiological, and behavioral outcomes 4 .
In our study, the objective parameters were focused on evaluating firing time, bleeding control, leaks after complete firing, and early postoperative complications that have not been published before.The results are similar to other prior studies examining the same selected outcome parameters compared to surgery performed with a non-powered system 1,2,10,20,23,45,46 .In our experience, the main advantage of using a motorized stapler is the total surgical time once finished the procedure.A subjective parameter difficult to evaluate is ergonomic advantages.For us, Ezisurg TM is lighter and easier to use than other motorized devices available in the market.

CONCLUSIONS
According to the results of this study, the motorized Ezisurg TM stapler offers safety and efficacy as revealed in prior reports, and is relevant since less total time of surgical procedure without intraoperative or postoperative complications were confirmed.However, further controlled prospective studies are needed to confirm the validity of these findings.
a) Total firing time for complete gastric transection; b) Number of firings to complete the surgical procedure; c) Number of clips used after complete firing according to the number of firings employed divided by the number of clips employed to obtain complete hemostasis of the suture line (Figure 1); d) Number of leaks observed after methylene blue intragastric installation; e) Intraoperative difficulties; and f) Total time of surgical procedure.After surgery, early outcomes were evaluated for: a) Early postoperative complications; b) Total in-hospital stay; and c) 30-day readmissions.

Table 2 -
Comorbidities in patients submitted to laparoscopic sleeve gastrectomy, laparoscopic Roux-en-Y gastric bypass, and laparoscopic distal gastrectomy.

Table 6 -
Postoperative outcome of patients comparing the type of stapler used for performing the procedure.